He's better/different than Goldy. Goldy is mostly just a rush player, not great when he doesn't have the puck on his stick. Both can waver defensively though your right on that.
Kaliyev is smarter, bigger, better shot. He's good at making plays too, and getting open to unleash his rocket of a shot. The one area Goldy has over him is skating, but Kaliyev is a better prospect overall IMO.